This invention relates to a massager which exerts a percussive massage effect.
Power-operated massagers are often used to treat muscle tension and fatigue. Massagers that exert a percussive effect on the body are preferred over massagers which generate a rubbing action, since the latter type of massager can cause irritation or other discomfort to the recipient.
U.S. Pat. No. 4,730,605 issued to Noble et al. discloses one such percussive massager. The massager has a casing with two handles, and is intended for two-handed operation. U.S. Pat. No. 5,716,332 issued to Noble discloses a similar percussive massager that is designed so as to be capable of use for self massage. In both massagers, the massage head is coupled to a base structure for pivotal rocking movement about a pivot axis for exerting a percussive massage effect.
More particularly, the massagers referenced above each include a weight is affixed to the drive shaft of the motor. The weight has a vertical arm attached eccentrically thereto, such that rotation of the drive shaft causes the vertical arm to move axially. The vertical arm is coupled to a first massage formation, which is in turn connected to a second massage formation by a rigid surface. Movement of the vertical arm causes the first massage formation to be moved upwardly and downwardly, and in turn causes the second massage formation to be moved in the opposite direction about a central pivot. Unfortunately, this design has the disadvantage that movement of the first and second massage formations are both controlled by the same vertical arm and are not moved independently. Consequently, if the vertical arm breaks, the movement of both massage formations ceases.
Therefore, it is a principal object of the present invention to provide a percussive massager having massage nodes that are moved independently.
Accordingly, a percussive body massager having independently movable massage nodes is provided. The massager has a housing that includes a massage head portion and a handle portion, and a motor support unit affixed within the massage head portion. A motor is supported by the motor support unit, and rotatably drives an output shaft that protrudes from either side of the motor. The massager further includes a pair of connecting rods each having a first end and a second end. The first ends of the connecting rods are operably connected to the output shaft such that rotation of the output shaft causes the connecting rods to reciprocate axially in an asynchronous manner. A rocker arm is attached to the motor support unit at a central pivot axis thereof and is operably connected to the second ends of the connecting rods. During rotation of the output shaft, the rocker arm is moved about the central pivot axis. At least two massage nodes are operably connected to the rocker arm to form a massage surface, wherein the massage nodes are moved asynchronously toward and away from the massage head portion by each of the connecting rods to provide a percussive massage effect.
In accordance with a preferred embodiment of the present invention, the pair of connecting rods are operably connected to the output shaft by a pair of crank arms affixed to each end of the output shaft. To provide the asynchronous movement, one connecting rod is attached to one crank arm in a first offset location with respect to a longitudinal axis of the output shaft, and the other connecting rod is attached to the other crank arm in a second offset location with respect to the longitudinal axis of the output shaft. Preferably, the first offset location is 180 degrees from the second offset location.
In further accordance with the preferred embodiment, the rocker arm includes connectors, such as screws, extending therefrom for securing the massage nodes to the rocker arm. Advantageously, the massage nodes can then be removed and interchanged with another set of massage nodes. The rocker arm preferably further includes protrusions and corresponding cavities formed in transversely spaced apart end portions of the rocker arm which are operably connected to the second ends of the connecting rods. Resilient sleeves are affixed to the interior of the housing and sized to receive the protrusions, and the sleeves are operable to expand and contract in response to movement of the rocker arm by the motor. In a preferred embodiment, the output shaft can be rotated at a plurality of speeds through actuation of a variable speed lever.
Still further, the housing is preferably constructed from a plastic material and assembled from a top housing part and a bottom housing part. According to a preferred embodiment, the massage nodes are hemispherically shaped, have an internal frame constructed from a plastic material, and have an exterior surface constructed from a resilient material to impart the percussive massage effect.
The above objects and other objects, features, and advantages of the present invention are more readily understood from a review of the attached drawings and the accompanying specification and claims.